Systems, devices and methods for delivery systems

ABSTRACT

Delivery systems for expandable and stented implants include adjustable tensioning members that control the expansion of the implant along the length of the implant. The tensioning members are wound onto one or more rotors located on the distal segment of the delivery system, which are rotated to unwind the tensioning members and incrementally expand the implant. Positioning mechanisms are also provided to adjust the position and orientation of the implant during delivery.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.17/179,308 filed Feb. 18, 2021, issued as U.S. Pat. No. 11,246,726 onFeb. 15, 2022, which claims priority to U.S. Provisional Application No.63/150,518 filed Feb. 17, 2021 and U.S. Provisional Application No.63/148,124 filed Feb. 10, 2021, which are incorporated herein byreference, in their entirety, for any purpose.

BACKGROUND

This patent application relates generally to the delivery of expandableand stented devices diseases, and more specifically to methods andapparatus for minimally invasive delivery of expandable or stentedimplants, such as into the cardiovascular system, such as heart valvereplacement.

Valvular heart disease is a significant burden to patients andhealthcare systems, with a prevalence of 2-3% worldwide, and with anincreasing prevalence in aging populations. Valvular disease may resultfrom a variety of etiologies, including autoimmune, infective anddegenerative causes. The epidemiology of valvular disease also varieswith the affected valve, with rheumatic heart disease being the causeworldwide of primary mitral regurgitation and mitral stenosis, but withsecondary mitral disease from left ventricular dysfunction being morecommon in developed countries.

While surgical repair and valve replacement remains a mainstay of manymitral valve therapies in the current clinical guidelines by theAmerican Heart Association and American College of Cardiology,transcatheter mitral repair is recommended for certain patientpopulations. In the 2017 Focused Update and the 2014 Guidelines forManagement of Patients with Valvular Disease, the AHA/ACC recommendedpercutaneous mitral valve balloon commissurotomy for severe mitral valvestenosis, and transcatheter mitral valve repair in certain severelysymptomatic patients with severe primary mitral regurgitation with areasonable life expectancy who are non-surgical candidates due tocomorbidities.

BRIEF SUMMARY

Further growth of transcatheter mitral valve therapies is challenged bythe difficulty by mitral valve anatomy and physiology, compared to moreestablished transcatheter aortic valve therapies. The tortuousanatomical pathways between the remote anatomical location and thetarget anatomical location often exerts stresses and strains on thedelivery system that can affect the concordance between the controls onthe proximal end of the delivery system and the effectors on the distalend of the device.

To facilitate the expansion and release at the target location, thedelivery system may include an adjustable radial tensioning system thatprovides control of implant expansion via extension of the tensioningmembers. The tensioning members are contained within the distal regionof the delivery system and therefore are not subject to stretching orslippage over the distances between the proximal control and distalregion of the delivery system, or from spring-out effects of expandableheart valves maintained in a collapsed configuration solely by aretention sheath.

In some further embodiments, the delivery system may also comprise oneor more steering or positioning mechanisms to facilitate finalpositioning and orientation of the implant at the target location,before and/or during expansion and release of the implant. Thepositioning mechanisms may include extension mechanisms which areconfigured to adjust the longitudinal position of a distal segment ofthe delivery system, without repositioning the entire delivery systemrelative to the patient's anatomy. Single axis and multi-axis steeringmechanisms may also be included to facilitate the insertion andnavigation of the delivery system through the anatomy, and to adjust thepose of distal segment of the delivery system and the implant during thedelivery procedure.

In one embodiment, a delivery system is provided, comprising a proximalhandle comprising a handle housing and a first actuator, a catheter bodycoupled to the handle, the catheter body comprising a distal section, aproximal section and a middle section therebetween, a rotatable driveshaft coupled to the first actuator and located in the catheter body, afirst stator housing attached to the catheter body, the first statorhousing comprising an internal opening and an external opening, a firstrotor attached to the rotatable drive shaft and located in the firststator housing, the first rotor comprising at least one tension lineattachment site, and a movable sheath located over the catheter body.The delivery system may further comprise a self-expanding implant, theimplant comprising a contracted configuration and an expandedconfiguration, and a first tensioning member releasably coupled to theself-expanding implant and fixedly coupled to the attachment site of thefirst rotor. The first tensioning member may be further wound around thefirst rotor, and may be wound around the first rotor at least threetimes. The delivery system may also further comprise a second statorhousing attached to the catheter body and spaced apart from the firststator housing, the second stator housing comprising an internal openingand an external opening, a second rotor attached to the rotatable driveshaft and located in the second stator housing, the second rotorcomprising at least one tension line attachment site. The deliverysystem may also further comprise a third stator housing attached to thecatheter body and spaced apart from the first and second statorhousings, the third stator housing comprising an internal opening and anexternal opening, a third rotor attached to the rotatable drive shaftand located in the third stator housing, the third rotor comprising atleast one tension line attachment site. The first stator housing may belarger than the second stator housing and the first rotor is larger thanthe second rotor. The first stator housing may be larger than both thesecond and third stator housings and the first rotor is larger than thesecond and third rotors. The proximal handle may further comprise afirst actuator lock, wherein the first actuator lock comprises lockedand unlocked configurations and is biased to the lock configuration. Thedelivery system may further comprise a catheter extension assemblyconfigured to reversibly adjust a longitudinal spacing between thedistal section and the middle section of the catheter body. The catheterextension assembly may comprise a proximal housing with a proximalthreaded lumen, a distal housing and a threaded extension shaft locatedin the proximal threaded lumen and coupled to the distal housing. Theproximal housing and distal housing may comprise a slotted interfacetherebetween to resist rotational displacement therebetween. Theproximal handle may further comprises a second actuator coupled to thethreaded extension shaft. The delivery system may further comprise afirst steering assembly comprising a first segmented tubular body and afirst plurality of elongate steering wires. The first steering assemblymay be located proximal to the catheter extension assembly. The firstsegmented tubular body may comprise a laser-cut tubular body. Thedelivery system may further comprise a second steering assemblycomprising a second segmented tubular body and a second plurality ofsteering wires. The second steering assembly may be located distal tothe catheter extension assembly. The first steering assembly and secondsteering assembly may comprise different bending configurations. Forexample, the first steering assembly may comprise a two-way steeringassembly and the second steering assembly may comprise a four-waysteering assembly. The first segmented tubular body may comprisesegments attached by living hinges. The second segmented tubular bodymay comprise a plurality of discrete segments. Each of the plurality ofdiscrete segments may comprise one or two non-planar end openings. Thenon-planar end openings comprise a hyperbolic paraboloid shape. Each ofthe plurality of discrete segments may comprises a perimeter bumperconfigured to slidably within a lumen of the distal section of thecatheter body.

In another embodiment, a minimally invasive implant delivery system isprovided, comprising a handle comprising first, second, third and fourthcontrols, a tubular catheter body attached to the handle, the catheterbody comprising a distal section, a middle section and proximal section,a catheter extension assembly configured adjustably extend the distalsection of the catheter body relative to the middle section, a firststeering assembly located proximal to the catheter extension assembly,and a second steering assembly located distal to the catheter extensionassembly. The implant delivery system may further comprise a main driveshaft coupled to the first control and extending through the firststeering assembly, catheter extension assembly and second steeringassembly, and an extension drive shaft extending through first steeringassembly and terminating at the catheter extension assembly, theextension drive shaft coupled to the second control. The first andsecond controls may comprise rotary dials. The first steering assemblymay be coupled to the third control and the second steering assembly iscoupled to the fourth control. The third control comprise a pivothandle. The fourth control may comprise a joystick. The first steeringassembly may be attached to a proximal end of the catheter extensionassembly and the second steering assembly is attached to a distal end ofthe catheter extension assembly. The first steering assembly may belocated within the middle section of the catheter body and wherein thesecond steering assembly may be located within the distal section of thecatheter body.

In still another embodiment, a method of delivering an expandableimplant is provided, comprising navigating an expandable implant to atarget location using a delivery catheter, using at least one of asteering assembly and a catheter extension assembly of the deliverycatheter to set the expandable implant in a target pose, withdrawing acatheter sheath to expose the expandable implant, and actuating at leastone rotor of the delivery catheter to unwind and extend at least onetensioning member from the delivery catheter to permit expansion of theexpandable implant, the at least one tensioning member attached to theexpandable implant. The method may further comprise further actuatingthe at least one rotor of the delivery catheter after expansion of theexpandable implant to permit separation of the at least one tensioningmember from the deliver catheter. The method may further compriseunlocking a rotor lock before or during the actuation of the at leastone rotor. Unlocking a rotor lock may comprise squeezing a rotor lockrelease of a delivery catheter handle and wherein actuating the at leastone rotor comprises rotating a rotor dial of the delivery catheterhandle. The squeezing of the rotor lock release and rotating the rotordial may be performed with a single hand.

In another embodiment, a method of loading an expandable stent structureonto a delivery catheter is provided, comprising providing an expandedstent structure attached to a plurality of tensioning members atdifferent locations of the expanded stent structure, inserting adelivery catheter through the expanded stent structure, attaching theplurality of tensioning members to a plurality of rotors located at adistal section of a delivery catheter, collapsing the stent structureonto the delivery catheter, rotating the plurality of rotors to wind theplurality of tensioning members onto the plurality of rotors, andextending a catheter sheath over the collapsed stent structure.Collapsing the stent structure may be performed by tensioning thetensioning members by rotating of the plurality of rotors, or bycollapsing the stent structure by pushing or pulling the expanded stentstructure through a tapered structure, for example.

In still another variation, a method for performing mitral valvereplacement is provided, comprising positioning a delivery devicecontaining a collapsed heart valve assembly in an orthogonal, centeredpose across the native mitral valve, wherein the heart valve assemblycomprises a self-expandable stent and attached valve leaflets,retracting a sheath of the delivery device to expose the collapsed heartvalve, rotating a first rotor to unwind and extend a first tensioningmember to permit expansion of a first end of the stent located in a leftatrium, and rotating a second rotor to unwind extend a second tensioningmember to permit expansion of a second end of the stent located in aleft ventricle. Rotating the first and second rotors are attached to acommon drive shaft but unwind the first and second tensioning members atdifferent lengths per rotation. The method may further compriseaccessing a femoral vein, inserting a transseptal puncture devicethrough the femoral vein and to the right atrium, puncturing theintraatrial septum, and inserting the delivery device with a collapsedheart valve assembly through the femoral vein and into the left atrium.Expanding the first end of the stent and expanding the second end of thestent may occur simultaneously but wherein the diameters of the firstand second rotors are different. The method may further comprisedilating the intraatrial septum. The method may also further compriseaccessing the left thoracic cavity through the chest wall, puncturingthe cardiac tissue at an apex of the left ventricle, and inserting thedelivery device with a collapsed heart valve assembly though the chestwall and transapically into the left ventricle, or may further compriseaccessing a femoral artery, and inserting the delivery device with acollapsed heart valve assembly through the femoral artery and aorticarch and into the left ventricle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A, 1B and 1C are top perspective, top plan and side elevationalviews, respectively of one exemplary embodiment of delivery system foran expandable implant.

FIGS. 2A to 2D schematically depict one configuration of a deliverysystem which simultaneously extends tensioning members at three rotorsof the delivery system.

FIGS. 3A to 3D schematically depict another configuration of anexemplary delivery system where a middle rotor is actuated first or to agreater degree than a proximal and distal rotor.

FIGS. 4A to 4E schematically depict another configuration of anexemplary delivery system for a double-wall stent in which the outerwall is expanded before the inner wall.

FIGS. 5A to 5E schematically depict another configuration of anexemplary delivery system for a double-wall stent in which the inner andouter walls are expanded simultaneously but at different rates.

FIG. 6 is a side view of the distal region of the delivery system inFIG. 6, without the sheath or the combination steering and extensionassembly.

FIG. 7 is a side cross sectional view of the distal region of thedelivery system in FIG. 1.

FIGS. 8A and 8B are a side cross sectional views of the rotor and statorregion of the delivery system, without and with an exemplary stentstructure, respectively.

FIGS. 9A and 9B are front and rear perspective views of the rotor shaft.FIGS. 9C and 9D are side elevational and side cross-sectional views ofthe rotor shaft in FIGS. 9A and 9B. FIGS. 9E and 9F are front and rearelevational views of the rotor shaft in FIGS. 9A and 9B.

FIGS. 10A and 10B are front and rear perspective views of the statorshaft. FIGS. 10C and 10D are side elevational and side cross-sectionalviews of the stator shaft in FIGS. 10A and 10B. FIGS. 10E and 10F arefront and rear elevational views of the stator shaft in FIGS. 10A and10B. FIGS. 10G and 10H are schematic cutaway views of a rotor/statorstructure depicting an exemplary configuration of the routing of atensioning member in an engaged and released configuration to arotor/stator and a stent structure; FIGS. 10I and 10J are schematiccutaway views depicting another configuration of the routing of atensioning member to a rotor/stator structure and a suture loop attachedto a stent structure, in an expanded and collapsed state.

FIG. 11 is a side elevational view of the steering and extensionassembly of the delivery system in FIG. 1.

FIG. 12 is a side elevational view of the distal steering assembly ofFIG. 11, in a bent configuration.

FIGS. 13A to 13F are top perspective, bottom perspective, top plan,bottom plan, side elevational and front/rear elevational views,respectively, of the proximal segment of the distal steering assembly inFIG. 12, with perimeter bumpers. FIGS. 13G to 13L are top perspective,bottom perspective, top plan, bottom plan, side elevational andfront/rear elevational views, respectively, of the proximal segment ofthe distal steering assembly in FIG. 12, without perimeter bumpers.

FIGS. 14A to 14F are top perspective, bottom perspective, top plan,bottom plan, side elevational and front/rear elevational views,respectively, of the middle segments of the distal steering assembly inFIG. 12, with perimeter bumpers. FIGS. 14G to 14L are top perspective,bottom perspective, top plan, bottom plan, side elevational andfront/rear elevational views, respectively, of the middle segments ofthe distal steering assembly in FIG. 12, without perimeter bumpers.

FIGS. 15A to 15F are top perspective, bottom perspective, top plan,bottom plan, side elevational and front/rear elevational views,respectively, of the distal segment of the distal steering assembly inFIG. 12, with perimeter bumpers. FIGS. 15G to 15L are top perspective,bottom perspective, top plan, bottom plan, side elevational andfront/rear elevational views, respectively, of the distal segment of thedistal steering assembly in FIG. 12, without perimeter bumpers.

FIGS. 16A and 16B are top perspective views of the combined proximalsteering and extension assembly, in a retracted and extendedconfiguration, respectively. FIG. 16C is a front elevational view of theextension assembly in FIGS. 16A and 16B, and FIG. 16D is a rearelevational view of the proximal steering assembly in FIGS. 16A and 16B.FIGS. 16E to 16H are top plan, top cross-sectional, side elevational andside cross-sectional views, respectively, of the combined proximalsteering and extension assembly of FIG. 16A in a retractedconfiguration. FIGS. 16I to 16L are top plan, top cross-sectional, sideelevational and side cross-sectional views, respectively, of thecombined proximal steering and extension assembly of FIG. 16B in anextended configuration. FIGS. 16M and 16N are detailed schematic viewsof various regions of the extension assembly. FIGS. 16O and 16P aredetailed cross-sectional views of the proximal steering assembly, withand without the steering element, respectively.

FIG. 17A is a top perspective view of the proximal handle in FIG. 1A.FIGS. 17B and 17C are side elevational and side cross-sectional views ofthe proximal handle in FIG. 17A. FIGS. 17D and 17E are superior plan andsuperior cross-sectional views of the proximal handle in FIG. 17A.

FIGS. 18A to 18C are perspective, top plan and side elevational views ofthe proximal handle in FIG. 17A, without the handle housing.

FIG. 19A depicts another embodiment of the delivery device, comprisingtwo two-way steering assemblies. FIGS. 19B to 19E depict the handle ofthe delivery device of FIG. 19A.

FIG. 20A is a schematic component view of another embodiment of thedelivery device, comprising an attachment interface in the distalcatheter section to provide attachment of the implant delivery section.FIG. 20B is a perspective view of the engagement of the implant deliverysection; FIG. 20C is a perspective view of the locking collar in thelocked position; FIG. 20D is a perspective view of the securement devicein the secured position.

FIG. 21A depicts the engagement of the attachment interface of the driveshaft, without the stator interface; FIG. 21B depicts the engagement ofthe attachment interface of the stator interface.

FIGS. 22 to 25 depict various exemplary configurations of the attachmentinterface to facilitate engagement of delivery system components.

DETAILED DESCRIPTION

FIG. 1 depicts one exemplary embodiment of a delivery system for atranscatheter heart valve replacement or other self-expanding stentstructure. The delivery system 100 comprises a handle 102 with one ormore actuators or user controls 104, 106, 108, 110, 130 and a catheterbody 112 extending distally. The catheter body 112 is located inside anouter sheath 114 which can be moved by the user via a sheath handle 116to sheath or expose a distal catheter section 118 with an atraumatic tipor nosecone 120 located at the distal end of the distal catheter section118.

The distal catheter section 118 comprises an implant deployment section122 that is configured to releasably retain a self-expanding implant(not shown) for delivery. The implant deployment section 122 includes arotor/stator assembly, described in greater detail below, that is usedto maintain the implant in a contracted or compressed configuration, andthat can be adjusted to incrementally permit implant expansion towardits expanded configuration. The length of the catheter body 112 exposedbetween the sheath handle 116 and the main handle 102 will correspondgenerally to the length of the implant deployment section 122. In somefurther variations, depending on the physical characteristics of theimplant and/or the delivery system, the rotor/stator assembly may alsobe used to contract or compress the implant back toward to thecontracted or compressed configuration. One or more tensioning membersthat are attached to the implant and wound around the rotors are used tocontrol the expansion and/or contraction of the implant. To facilitatethe positioning and/or orientation of the implant deployment section 122during the procedure, one or more steering or positioning mechanisms124, 126, 128 may be provided along the catheter body 112, and aredescribed in greater detail below.

Once the implant is expanded to the desired size and location, thedelivery system may be separated from the implant in any of a variety ofways. For example, the one end or a middle portion of a tensioningmember may be adhered, knotted or coupled by a friction fit to a rotor,while the other end or both ends of the tensioning member may bereleasably attached to a clamp or other retention member located in thedistal catheter section or in the handle of the delivery system. Inother examples, the end(s) of the tensioning member may be severed by acutting mechanism to separate the tension line from the implant or fromthe delivery system, e.g. where the tension line is retained on theimplant after separation. In still other examples, the tensioning membermay be transiently coupled to the rotor via one or more windings of thetensioning member that hold the tensioning member against the rotor.Upon further unwinding of the tensioning member, the end(s) of thetensioning member may be released, to allow the tensioning member to bepulled out of the implant for removal along with the delivery system.

The rotor/stator assembly may comprise any of a variety ofconfigurations. In one embodiment, depicted in FIGS. 2A to 2D, theimplant deployment section 200 of the delivery system includes distalelongate body 202 from which the implant or stent 216 is released. Thedistal elongate body 202 includes multiple rotors/stators 204, 206, 208spaced along the longitudinal length of the implant deployment region202. As a drive shaft inside distal elongate body 202 is rotated, thetension lines 210, 212, 214 are unwound from the rotors/stators 204,206, 208 in generally equal tension line lengths/rotation. The rotationof the drive shaft may be manipulated by the user at a control or knob104 located in handle 102, as depicted in FIGS. 1A to 1C. The handle mayalso include a user releasable lock 130 that is holds the control ofknob 104 in place, to avoid inadvertent release or expansion of theimplant. In other examples, the knob 104 may comprise an auto-lockingmechanism, e.g. a knob that is biased to the lock position by a springthat and must be pushed longitudinally to disengage and rotate the knob.Description of the exemplary knob 104 and the lock 130 are provided ingreater detail below. This results in the stent implant 216 expansion inFIGS. 2B and 2C occurring equally along the length of the implant 216.Once expanded against the surrounding anatomical structure, the tensionlines 210, 212, 214 may be separated from the implant 216 by furtherunwinding of the tension lines 210, 212, 214 until the tensioningmembers 210, 212, 214 are freed from self-binding to the rotors/stators204, 206, 208, as schematically depicted in FIG. 2D. Although thedepicted embodiment in FIGS. 2A to 2D includes three equally spacedapart rotors/stator 204, 206, 208, in other variations, a differentnumber of rotors/stators may be provided and the spacing may bedifferent between them, depending the implant configuration and thetarget location. In other variations, number of rotors/stators may be inthe range of 2 to 4, 1 to 3 or 2 to 3, for example.

FIGS. 3A to 3D depict another variation of the delivery system, whereinthe implant deployment region 300 comprises a distal includes multiplerotors/stators 302, 304, 306, which may be configured to either unwindthe tensioning members 308, 310, 312 at different rates per unitrotation, or in a sequential manner. In the depicted embodiment, themiddle rotor/stator 304 on the implant deployment region 300 isconfigured to unwind a greater length of tensioning member 310 thaneither proximal or distal rotors/stators 302, 306, to allow the middlesection 316 of the implant 314 to expand first or to a greater degreethan the ends 318, 320 of the implant 314. This may facilitatepositioning of the implant 314 in some procedures at the target locationby aligning the expansion of the middle section 316 implant 314 ratherthan the ends 318, 320, which may be more difficult to align due toforeshortening of the implant 314. This may be provided by configuringthe middle rotor/stator 304 with a larger diameter for wrapping aroundthe tensioning members compared to the proximal or distal rotors/stators302, 206, which increases the length of tensioning member per rotationof the rotor. The length per rotation may also be altered by providing adifferent number of tensioning members at each rotor/stator. A greaternumber of tensioning members as they are wrapped around the rotor willresult in a larger diameter from all of the coiled tensioning members,which will provide an increased initial length per rotation duringdeployment. In other examples, multiple drive shafts (not shown) may beprovided to independently drive one or more rotors/stators withdifferent amount of rotation relative to one or more otherrotors/stators. The multiple drive shafts may comprise a concentricconfiguration with a solid inner drive shaft for one or more distalrotors/stators, a tubular drive shaft for one or more proximalrotors/stators, for example, or multiple parallel drive shafts, eachterminating at a different rotor/stator, for example.

FIGS. 4A to 4D depict still another embodiment of a delivery system 400,wherein the implant deployment region 420 of the catheter includesmultiple rotors/stators 422, 424, 426 used to deliver a double-wallstented structure, such as the unibody folded stent heart valve implant804 as described in U.S. application Ser. No. 17/083,266, which ishereby incorporated by reference in its entirety. In this configuration,the distal rotor/stator 426 is actuated first, before the middle andproximal rotors/stators 422, 424.

Referring to FIG. 4A, the delivery system 400 with the delivery catheter402 and valve 404 is positioned across the mitral valve opening 406. Thedelivery system 400 may also be further manipulated to adjust the angleof entry through the mitral valve opening 406 to be roughly orthogonalto the native valve opening and/or to be centered with the mitral valveopening 406. Once the desired catheter pose is achieved, the deliverysheath 408 is withdrawn proximally, to expose the collapsed valve 404.

In FIG. 4B, the first set of tension lines 428 controlling the releaseof the downstream or ventricular end 410 of the outer wall 412 of thevalve 404 is partially released, while the tension lines 430, 432controlling the inner wall 416 remain tensioned. Next, in FIG. 4C,ventricular end 410 of the outer wall 412 of the valve 404 is furtherreleased, allowing the ventricular end, the middle region and more ofthe atrial end 414 of the outer wall 412 to expand further, therebyallowing the transition wall 416 of the valve 402 to at least partiallyexpand outward. The partial expansion of the atrial end 414 and theventricular end 410 of the valve 402 helps to further center and orientthe middle region 422 of the valve 402 orthogonally prior to completerelease. While the initial expansion of the atrial end 414 of the outerwall 412 in this embodiment is a secondary effect from the partialrelease of the ventricular end 410 of the valve 402 as longitudinaltension is released, in other examples, independent tension line controlof the atrial end 414 may be provided.

In FIG. 4D, the tension lines of the ventricular end 410 and atrial end414 are further released, either simultaneously or singly in a stepwisefashion, further engaging the middle region 420 of the outer wall 412against the valve opening 406. This further expansion of the outer wall412 also exposes the retention barbs or projections 422 on the outerwall 412. Proper centering and orientation of the valve is reconfirmed,to make sure the valve has not been deployed in a skewed or partiallydisengaged pose with respect to the mitral valve annulus. In somevariations, the tension lines may be re-tensioned to re-collapse thevalve 404, to facilitate re-positioning and/or re-orienting of the valve404. Once confirmed, the tension lines 430, 432 of the inner wall 418may be released, as shown in FIG. 4E, which also allows the outer wall412 to achieve its untethered expansion against the mitral valve opening806. The outer wall 412 may also be expanded first against the valveopening 806, with the tension lines 430, 432 released afterwards. Thetension lines 428, 430, 432 can then be cut or otherwise released orseparated from the valve implant as described herein and the tensionlines 428, 430, 432 may be withdrawn into the catheter and optionallyout of the proximal end of the catheter. The delivery catheter andguidewire can then be withdrawn from the patient and hemostasis isachieved at the femoral vein site.

FIGS. 5A to 5D depict still another embodiment of a delivery system 500,wherein the implant deployment region 520 of the catheter includesmultiple rotors/stators 522, 524, 526 that are located on the same driveshaft (not shown) and used to deliver a double-wall stented heart valvestructure. In this configuration, all three rotors/stators 522, 524, 526are configured to rotate simultaneously and with equal degrees ofrotation, though the length of the tensioning member 428, 430, 432 thatis extended or retracted per unit of rotation may be different,depending on the diameter of the rotor and/or the number of tensioningmembers.

Referring to FIG. 5A, the delivery system 500 with the delivery catheter502 and valve 504 is positioned across the mitral valve opening 506. Thedelivery system 500 may also be further manipulated to adjust the angleof entry through the mitral valve opening 506 to be roughly orthogonalto the native valve opening and/or to be centered with the mitral valveopening 506. Once the desired catheter pose is achieved, the deliverysheath 508 is withdrawn proximally, to expose the collapsed valve 504.

In FIGS. 5B to 5D, all three sets of tension lines 528, 530, 532controlling the release of the downstream or ventricular end 510 of theouter wall 512 and the inner wall 518 of the valve 504 aresimultaneously incrementally released, although tension lines 528 may beconfigured to release at a greater rate than tension lines 530, 532 dueto the greater amount of travel of the ventricular end 510 of the outerwall 512 exhibited during expansion compared the inner wall 518. Next,in FIG. 5C, ventricular end 510 of the outer wall 512 of the valve 504is further released, allowing the ventricular end, the middle region andmore of the atrial end 514 of the outer wall 512 to expand further,thereby allowing the transition wall 516 of the valve 504 to at leastpartially expand outward. The partial expansion of the atrial end 514and the ventricular end 510 of the valve 504 in conjunction with thepartial expansion of the inner wall 518 helps to further center andorient the middle region 520 of the valve 504 orthogonally prior tocomplete release. While the initial expansion of the atrial end 514 ofthe outer wall 512 in this embodiment is a secondary effect from thepartial release of the ventricular end 510 of the valve 504 aslongitudinal tension is released, in other examples, independent tensionline control of the atrial end 514 may be provided.

In FIG. 5D, the tension lines 528, 530, 532 of the ventricular end 510and inner wall 518 are further released simultaneously, further engagingthe middle region 520 of the outer wall 512 against the valve opening506. This further expansion of the outer wall 512 also exposes theretention barbs or projections 522 on the outer wall 512. Propercentering and orientation of the valve is reconfirmed, to make sure thevalve has not been deployed in a skewed or partially disengaged posewith respect to the mitral valve annulus. In some variations, thetension lines may be re-tensioned to re-collapse the valve 504 may beperformed, to facilitate re-positioning and/or re-orienting of the valve504. Once confirmed that the outer wall 512 has achieved its desiredexpansion against the mitral valve opening 506, as shown in FIG. 5E, thetension lines 528, 530, 532 can then be cut or otherwise released orseparated from the valve implant as described herein and the tensionlines 528, 530, 532 may be withdrawn into the catheter and optionallyout of the proximal end of the catheter. The delivery catheter andguidewire can then be withdrawn from the patient and hemostasis isachieved at the femoral vein site.

FIGS. 6 and 7 depict an exemplary detailed configuration of the distalcatheter section 118 of the distal delivery system 100 in FIGS. 1A to1C. As noted previously, the distal catheter section 118 includes a nosecone 120 to facilitate insertion and navigation of the delivery system100 along the anatomical pathway. The nose cone 120 may include aguidewire lumen and distal opening (not shown) and may comprise a softatraumatic material such as nylon, polyurethane, or silicone, forexample. The nose cone 120 is attached to the stator assembly 600 withat least one stator housing 604, 606, 608 spaced along the stator body602. Inside the tubular stator body 602 and the stator housings 604,606, 608 is a rotor body (not shown) with a rotors 610, 612, 614, uponwhich the elongate tension lines are attached and wound around. Openingsin the stator housings 604, 606, 608 permit the tension lines to extendand optionally retract as the rotor body is rotated.

The proximal end of the tubular stator body 602 is attached to aflexible tubular drive shaft casing 616 in which a flexible drive shaftresides. The drive shaft casing 616 may be located within one or moresteering and/or positioning assemblies 124, 126, 128 that may beprovided in the delivery system 100. In this particular embodiment, aproximal steering assembly 124 is directly coupled at its distal end toa proximal end of a catheter extension assembly 126. In turn, the distalend of the catheter extension assembly 126 is directly coupled to adistal steering assembly 128. Examples of the steering and extensionassemblies are described in greater detail below.

Referring now to FIGS. 8A and 8B, exemplary embodiments of a statorassembly 800 and a rotor assembly 850 are depicted in greater detail.The stator assembly 800 comprises a tubular stator body 802, comprisinga plurality of tubular body segments 802 a-d that are connected bystators 804 a-c. The lengths of the segments 802 a-d may be the same ordifferent. In this particular embodiment, the end segments 802 a, 802 dhave a similar length, while the middle segments 802 b, 802 c are eachlonger than the end segments 802 a, 802 d and with the proximal middlesegment 802 b having a greater length than the distal middle segment 802c. The segments 802 a-d form a longitudinal lumen 812 along the lengthof the stator assembly 800 in which the rotor assembly 850 resides.

Each of the stators 804 a-c comprises a housing that is generallycylindrical in shape, but may also be configured with otherthree-dimensional shape shapes, e.g. frustoconical, square box,rectangular box, trapezoidal box, etc. Each stator 804 a-c comprises aproximal end wall 816 a-c, a distal end wall 818 a-c, and a lateral wall820 a-c. The proximal end walls 816 a-c and distal end walls 818 a-c mayinclude a central opening 822 a-c, 824 a-c, respectively, configured toreceive a stator body segment 802 a-d, and an inner opening 826 a-cthrough which the rotors of the rotor assembly may project from and intothe stator cavities 828 a-c. As depicted in FIG. 8B, the proximal anddistal end walls 816 a-c, 818 a-c may also comprise peripheral openings830 a-c, 832 a-c through which the tension lines 834 a-c may be routedthrough. The lateral walls 820 a-c may also comprise one or more lateralopenings 836 a-c.

The rotor assembly 850 comprises a rotor shaft 852 with a longitudinallumen 854 through which a guidewire may be inserted. Spaced apart on therotor shaft 852 are rotors 856 a-c that extend out radially from therotor shaft 852 at the stator body gaps 814 a-c located between thestator body segments 802 a-d. The rotors 856 a-c may comprise a circularshape as depicted herein, but in other variations, may comprise an ovalshape or polygonal shape. Each of the rotors 856 a-c may comprise one ormore attachment structures 858 a-c for attaching a tension line 834 a-c.The attachment structures 858 a-c may comprise an opening through therotor 856 a-c that allows the tension line 832 a-c to be wound around orto be unwound from the rotor 856 a-c, rotor shaft 852 or tubular bodysegment 802 b, 80 c. The radial distance from the longitudinal axis ofthe delivery system to the attachment structures 858 a-c and/or to theperipheral end openings 830 a-c, 832 a-c may be configured, depending onthe implant configuration and/or angle of the tension lines 832 a-c asthey exit the peripheral end openings 830 a-c, 832 a-c during implantexpansion. Each of the rotors 856 a-c and stators 804 a-c may have morethan one tension line 832 a-c attached to it, and each of the tensionlines may have a different length. For example, rotor 856 c may havefour tension lines 832 c attached, which each tension line 832 c exitingthe stator 804 c at a different end opening 830 c and spaced 90 degreesapart from each other, while rotors 804 a and 804 b may be configuredwith three tension lines 832 a, 832 b each, spaced 120 degrees apart butwherein tension lines 832 a and 832 b have a different line length,which may result from different degrees of expansion along the implant.In other variations of the delivery system, the one, two or fourrotors/stators may be provided, and the number of tension lines for eachrotor/stator may be one, two, five, six, seven, eight, nine, twelve orany range therebetween. The lengths of each tension line or tension loopmay be 10 mm to 70 mm, 15 mm to 60 mm, or 20 mm to 40 mm. The diameterof a stator body may be in the range of 2 mm to 8 mm, 3 mm to 5 mm or 6mm to 8 mm. As noted previously, the distal stator may comprisedifferent diameter than the other stators, in the range of 5 mm to 10mm, 6 mm to 8 mm, or 6 mm to 7 mm. The proximal and/or middle stator maycomprise a diameter in the range of 3 mm to 8 mm, 4 mm to 6 mm, or 4 mmto 5 mm. The radial distance from the longitudinal axis to theattachment structure of a rotor may be in the range of 0.7 mm to 3.75mm, 1 mm to 2.9 mm, or 1.5 mm to 2 mm.

FIGS. 9A to 9F illustrates another variation of a rotor assembly 900,comprising a tubular shaft 902, a proximal rotor 904 a, a middle rotor904 b and a distal rotor 904 c. Each rotor 904 a-c comprises a mount,ring or tubular body 906 a-c to couple to the shaft 902, with adisc-like flange 908 a-c. Each mounting ring 906 a-c includes a centralopening 910 a-c to receive the shaft 902 and may include one or moreoptional sidewall openings 912 a-c which may be used to facilitate thebonding of the rotors 904-ac. The distal rotor 904 c has a larger flange908 c than the flanges 908 a, 908 b of the proximal and middle rotors904 a-b. The larger size allows a greater number of tension lines to beattached. Each flange 908 a-c comprises one or more attachmentstructures for the attachment of the tension lines. The attachmentstructures may comprise projections or openings on the flange 908 a-c.In the particular embodiment depicted in FIGS. 9A to 9F, the distalflange 904 c comprises four sets of apertures 914 a-d, with each setcomprising a larger oblong opening 916 a along the outer diameter of theflange 908 c, and along with three smaller openings 916 b-d along theinner diameter of the flange 908 c, with the larger opening 916 asymmetrically radially aligned with the smaller openings 916 b-d. Eachof the aperture sets 914 a-d is equally spaced 90 degrees apart aroundthe flange 908 c, but in other examples may have a non-uniform spacing,or spacing that is bilaterally symmetrical but not circumferentiallysymmetrical.

In this particular embodiment, the proximal and middle flanges 908 a,908 b of the rotors 904 a, 904 b have the same shape but are mounted onthe rotor shaft 902 with their mounting rings 906 a, 905 b away from theother, with the proximal rotor mounting ring 906 a located proximal ofits flange 908 a, while the middle rotor 904 b has a mounting ring 906 bthat is distal to its flange 908 b. The distal mounting ring 906 c isalso distal to its flange 908 c. In other examples, however, one or moreof the rotors may have the opposite orientation. In still othervariations, the rotor may comprise a different configuration, e.g. withtwo flanges, or two or more mounting ring sections on each side of eachflange.

The length of the rotor shaft 902 may be in the range of about 10 mm to80 mm, 20 mm to 65 mm or 35 mm to 45 mm. The distance between any twoadjacent rotors may be in the range of about 5 mm to 60 mm, 10 mm to 50mm or 20 mm to 30 mm. In embodiments with a middle rotor, the distancebetween the proximal rotor and middle rotor may be in the range of about5 mm to 40 mm, 7 to 30 or 10 mm to 15. The distance between the middlerotor and the distal rotor may be in the range of about 25 mm to 30 mm,20 mm to 40 mm or 10 mm to 60 mm. The thickness of each rotor may be inthe range of about 0.35 mm to 0.40 mm, 0.3 mm to 0.5 mm or 0.2 mm to 0.6mm.

The outer diameter of the rotor shaft 902 may be in the range of about 1mm to 3 mm, 1.2 mm to 2 mm or 1.4 mm to 1.8 mm, while the diameter ofthe internal lumen 918 of the rotor shaft 902, if provided, may be inthe range of about 0 mm to 1.5 mm, 0.5 mm to 1.2 mm or 0.80 mm to 1.0mm. The diameter of the mount or ring 904 a-c may be in the range ofabout 1.2 mm to 3.5 mm, 1.6 mm to 3.0 mm or 2.0 mm to 2.4 mm. Thediameter of the rotor flange 908 a-c may be in the range of about 2 mmto 9 mm, 4 mm to 7 mm or 2 mm to 5 mm, 3.5 mm to 4.5 mm, 5 mm to 6 mm,4.5 mm to 7 mm.

Referring now to FIGS. 10A to 10F, the stator assembly 1000 may comprisea tubular stator shaft 1002, which itself may comprise one or moretubular shaft segments 1002 a-d, which are connected in a spaced apartfashion by corresponding proximal, middle and distal stator housings1004 a-c, respectively. In this particular embodiment, the proximal andmiddle stator housings 1004 a, 1004 b have the same size andconfiguration, while the distal stator housing 1004 c comprises a largersize and a different configuration. Each stator 1004 a-c may comprise agenerally cylindrical shape, with a proximal or first end wall 1006 a-c,distal or second end wall 1008 a-c and cylindrical or lateral wall 1010a-c therebetween, but in other variations may comprise a frustoconicalshape, oval or oblong shape, square box shape, rectangular box shape,triangular box shape or other polygonal box shape. The end walls 1006a-c, 1008 a-c each comprise three or four oval or oblong openings 1014a-c, 1016 a-c, respectively, that are equally spaced around the centeropenings 1018 a-c, 1020 a-c in which the stator shaft segments 1002 a-dare located. The cylindrical walls 1010 a-c of the housings 1004 a-ccomprise three or four larger oval openings 1018 a-c with twolongitudinally aligned smaller circular openings 1020 a-c locatedbetween each of the larger oval openings 1018 a-c. The number ofopenings may correspond with the number tensioning members provided ateach location, e.g. three tensioning members at each of the smallerstator housings with three openings, and four tensioning members at thelarger stator housing with four openings. The larger oval openings 1018c are equally spaced apart at 90 degrees, and each of the smaller pairsof openings 1020 c are also equally spaced apart at 90 degrees. Ofcourse, in other variations, a different number of the end andcylindrical wall openings may be provided on each wall 1006 a-c, 1008a-c, 1010 a-c, e.g. one, two, three four, or five of each type ofopening, and the openings may or may not equally spaced apart. Each ofthe stator housings 1004 a-c is configured with a cavity 1022 a-c thatis of a sufficient size to allow receive and to permit rotation of thecorresponding rotor, and manufactured with shaft segment gaps 1024 a-cto also receive and to permit rotation of the corresponding rotor. Theend walls 1006 a-c, 1008 a-c and the cylindrical walls 1010 a-c may alsocomprise one more projections 1026 a-c and/or recesses 1028 a-c toprovide a mechanical or friction fit to facilitate assembly of thestator housings 1004 a-c.

The length of the stator shaft 1002, including the shaft segment gaps1024 a-c, may be in the range of about 25 mm to 80 mm, 40 mm to 70 mm or55 mm to 65 mm. The stator shaft 1002 length may be longer or shorterthan the rotor shaft length, and the difference in rotor/stator shaftlength may be in the range of about ±0.2 mm to ±3 mm, 0.4 mm to 2 mm or0.4 mm to 0.8 mm. The outer diameter of the stator shaft may be in therange of about 1.6 mm to 3.3 mm, 1.7 mm to 3 mm or 1.8 mm to 2.5 mm,while the diameter of the stator internal lumen may be in the range ofabout 1.6 mm to 3.3 mm, 1.7 mm to 3 mm or 1.8 mm to 2.5 mm. The variousdistances between the stators may otherwise be similar to the variousdistance ranges as recited above for the distances for the correspondingrotors. The outer length of the stator housings may be in the range ofabout 3 mm to 8 mm, 4 mm to 7 mm or 5 mm to 6 mm, and the outerdiameters of the stator housings may be in the range of about 4 mm to 5mm, ***6 mm to 7 mm, 2 mm to 8 mm, 5 mm to 9 mm, or 3 mm to 8 mm. Theinternal cavities of the stator housings may have a length in the rangeof about 3 mm to 5 mm, 3 mm to 6 mm or 4 mm to 5 mm, and a diameter inthe range of about 4 mm to 6 mm, 3 mm to 5 mm, 5 mm to 7 mm, 4 mm to 7mm, 3 mm to 8 mm, 4 mm to 9 mm. The shaft segment gaps lengths may be inthe range of about 1 mm to 4 mm, 1 mm to 3 mm or 1.5 mm to 2.5 mm.

FIG. 10G is a schematic illustration of the routing configuration for atensioning member 1050 about a rotor 1052, stator housing 1054 and astent 1056. For clarity, only one of the multiple tensioning membersthat would be spaced around at different angular positions of therotor/stator location is shown. A first end 1058 of the tensioningmember 1050 is knotted or otherwise attached to an opening 1060 of therotor flange 1062 to resist separation from the rotor 1052. Thetensioning member 1050 is then routed out of a first stator opening 1064and into a second stator opening 1066 on the other side of the rotorflange 1062 and out of an end opening 1068 of the stator 1056. Thetensioning member 1050 would then extend out and as a loop segment 1070through an opening 1072 of the stent 1056, or multiple such openings andthen route back into the end opening 1068, the second stator opening1066 and the first stator opening 1064. The tensioning member 1050 wouldthen be wrapped around the rotor 1052 two, three, four, five or moretimes forming coils 1074, along with the other tensioning members atthat location, even wrapping around itself and/or other tensioningmembers. This number of wrapped loops or coils provides sufficientfrictional resistance so to resist unwrapping or slippage from theexpansion force of the stent 1056, depending on the tensioning membermaterial. The other, free end 1076 of the tensioning member 1050 mayextend out of the opposing end opening 1076 of the stator 1054.

When the stent 1056 is in a collapsed state, most of the tensioningmember 1050 will be within the stator 1054 or in contact with the stator1054, wrapped around the rotor 1052. As the rotor 1052 is rotated tounwind or unwrap the tensioning member 1050 from the stator 1052, thetensioning member 1050 will slide along its routing path to extend theloop segment 1070 through the end opening 1068, which permits the stentto further expand. In FIG. 10H, as the tensioning member 1050 furtherunwraps from the rotor 1052, the friction between the rotor 1052 and thecoils 1074 of the tensioning member 1050 will decrease to a point wherethe free end 1076 of the tensioning member 1050 is able to disengage andbe pulled out of from the rotor 1052 and out of the stator 1054. Furtherrotation of the rotor 1052 will begin to recoil or rewrap the tensioningmember 1050 beginning at the attached or knotted end 1058 of thetensioning member 1050 until the free end 1076 is pulled out of thestent 1056. In other variations, as long as the free end 1076 has beenreleased from the rotor 1052 and stator 1054, the further rotation ofthe rotor 1052 is not performed to partially recoil or fully recoil thetensioning member 1050 before the delivery system is withdrawn. Instead,the tensioning member 1050 can be fully separated from the stent 1056 bywithdrawing the delivery system with the tensioning member 1050 stillextending out from the stator 1054.

FIGS. 10I and 10J depicts another variation of the attachment of thetensioning member 1050 to the stent 1056. This variation is similar tothe prior variation in FIGS. 10G and 10H, except that instead of thetensioning member 1050 looping through an opening 1072 of the stent1056, the stent 1056 further comprises a flexible suture or attachmentloop 1080 located around one or more circumferences of the stent 1056.The attachment loop 1080 is permanently attached to the stent 1056 andis left with the stent 1056 after the delivery system is withdrawn. Theattachment loop 1080 may comprise the same or different material as thetensioning member 1050. The tension members and the attachment loop maycomprise a monofilament or a multifilament man ultra high molecularweight polyethylene, including but not limited to nylon, polyethylene,FORCE FIBER® suture (TELEFLEX MEDICAL, Gurnee, Ill.), liquid crystalpolymer suture, including but not limited to VECTRAN™ (KURARAY AMERICA,Tokyo, Japan), braided aramid fiber, including but not limited toKEVLAR® (DUPONT™, Wilmington, Del.), multi-strand metal wire, includingbut not limited to stranded stainless steel wire rope and tungsten wirerope, for example. The attachment loop 1080 may be configured with a netlength that is or corresponds to the circumference of the stent 1056when at its full expansion size, within 5%, 10%, 15%, 20% or 25% of thecircumference. As shown in FIG. 10J, as the stent collapses into itsdelivery configuration, the a portion 1082 of the attachment loop 1080that is attached to the loop 1070 of the tensioning member 1050 is ableto be pulled away from the stent 1056 and can invaginate or be pulledinto the stator housing 1056 or even coiled around the rotor 1052. Insome variations, the use of an attachment loop 1080 on the stent 1056may provide a more predictable coiling, release or other interactionswith the tensioning member 1050, by allowing the tensioning member 1050to slide along the circumference of the loop, rather than restrictingits attachment at a specific location of the stent 1056. This may reducethe risk of unintended snagging or cutting or the tensioning membersduring loading or delivery, and/or uneven tensioning forces betweendifferent tensioning members during loading or delivery.

As noted previously, in some variations, one or more steering orcatheter extension assemblies may be provided to facilitate navigationof the delivery system and/or positioning and orienting the deliverysection or implant during the procedure. In embodiments with two or moreof such assemblies, the assemblies may be spaced apart along thedelivery system, or as shown in FIG. 11, the assemblies 124, 126, 128may be subassemblies that are directly attached end-to-end, as a singleassembly 1100. In this particular embodiment, assemblies 124, 128 arebending or steering assemblies that are configured to bend the deliverysystem along one or multiple axes. In this example, the proximal bendingassembly 124 is a two-way bending assembly that it is configured to bendin a single plane in two opposite directions, while the distal bendingassembly 128 is a four-way bending assembly in that it is bends in atleast two planes and optionally in combinations of the bends in the twoplanes, e.g. multi-axial steering/bending. Between the two steeringassemblies 124, 128 is an extension assembly 126 that is configured toreversibly adjust its length or spacing between its proximal and distalends. This allows the user to make incremental changes to thelongitudinal positioning of the distal region of the delivery system,without requiring longitudinal displacement of the entire deliverysystem. Although this particular configuration comprises two differentconfigurations of steering assemblies, in other variations, the steeringassemblies may comprise the same configuration, or the order of thesteering assemblies may be reversed, and/or the extension assembly maybe located before or after the two steering assemblies.

Referring to FIGS. 12-15L, the distal steering assembly 128 may comprisea segmented tubular or ring configuration, with each segment 1300, 1400,1500 comprising one or two segment interface ends, depending on thelocation of the segment 1300, 1400, 1500 in the assembly 128. In thedepicted example of FIGS. 1A-1C, the distal steering assembly 128 may becontrolled by a joystick controller 108 on the handle 102, as describedin greater detail below. Referring back to FIGS. 12 to 15L, the proximaland distal segments 1300, 1500 each comprise a segment interface end1302, 1504 which is configured to interface with a segment interface end1402, 1404 of a middle segments 1400. The interface ends 1402, 1404 arealso configured to interface with the complementary other configurationof end 1402, 1404 of another middle segment 1400. The segment interfaceends 1302, 1402, 1404, 1504 are configured as a single-axis, two-waybend at each articulation between the interface ends 1302, 1402, 1404,1504 but with the distal steering assembly 128 comprising interfaceswith different orientations, e.g. one set of interfaces 1302, 1402having an orthogonal orientation to the other set of interfaces 1404,1504, the assembly 128 as a whole is configured as a four-way, two axisbending assembly.

Referring to FIGS. 13A-13F, 14A-14F, and 15A-15F, the proximal anddistal segments 1300, 1500 comprises a non-planar end 1302, 1504 thathas a hyperbolic paraboloid shape that is configured to interface with acomplementary non-planar end 1402, 1404 of a middle segment 1400 thatalso has a hyperbolic paraboloid shape. The non-planar end 1402 of themiddle segment 1400 is also configured to interface with the non-planarend 1404 of another middle segment 1400. At the upper regions 1312 ofthe end 1302, an alignment structure 1314 may be provided to interfacewith an alignment structures 1414 at the upper regions 1412 of thecomplementary end 1402 of the middle segment 1400. In this particularvariation, the alignment structure 1314 comprises a middle protrusion1316 flanked by indents or recesses 1318 which forms a complementaryinterface with the alignment structure 1416 of the middle segment 1400,which comprises a middle recess 1418 flanked by protrusions 1418.Likewise, the upper regions 1420 of the other end 1404 of the middlesegment 1400 comprises an alignment structure 1422 with a middleprotrusion 1424 flanked by indents or recesses 1426 that can also form acomplementary interface with the alignment structure 1404 of the middlesegment 1400, and also the alignment structure 1522 in the upper regions1520 of the non-planar end 1504 of the distal segment 1500. Thealignment structures 1522 on the distal segment 1500 are the same orsimilar to the alignment structure 1422 of the middle segment 1400, witha middle recess 1524 flanked by two protrusions 1526. The alignmentstructures 1314, 1414, 1422, 1522 are configured to still provide alimited amount of pivoting between the segments 1300, 1400, but do notlock the two segments 1300, 1400 together. In other variations, however,the alignments structures 1314, 1414, 1422, 1522 may comprisecomplementary ball-in-socket structures or other type of complementaryinterference structures that does lock the segments 1300, 1400 together.Also, in other variants, instead of a hyperbolic paraboloid shape, thenon-planar ends 1302, 1402, 1404, 1504 may comprise two planar sectionsthat are non-orthogonal to the longitudinal axis of the bending assembly128.

Referring still to FIGS. 13A-13F, 14A-14F, 15A-15F, each of the segments1300, 1400, 1500 comprises a center or primary opening 1330, 1430, 1530through which the drive shaft of the delivery system may reside.Segments 1300, 1400 further comprise bending openings 1332, 1432, 1532in which a steering wire or element may reside. In other examples,however, the distal segment 1500, may comprise attachment structures towhich the steering wires or elements attach, rather than pass through toattach to structures distal to the distal segment. The bending openings1332, 1432, 1532 may be orientated such that they are spaced 90 degreesapart, and spaced 45 degrees apart from an adjacent alignment structure1314, 1414, 1514.

As depicted in FIGS. 13G-13L, 14G-14L, 15G-15L, each of the segments1300, 1400, 1500 may also comprise one or more openings 1334, 1434, 1534and protrusions 1336, 1436, 1536. In some examples, the protrusions1436, 1536 may reinforce the segments 1300, 1400, 1500 where the bendopenings 1332, 1432, 1532 are located, and/or may facilitate thecoupling or attachment of the segment 1300, 1400, 1500 to the othercomponents of the delivery system. In the variants depicted in FIGS.13A-13F, 14A-14F, 15A-15F, polymeric jackets or bumpers 1338, 1438, 1538are provided around the segments 1300, 1400, 1500. These jackets orbumpers 1338, 1438, 1538 may help to disperse or redistribute thebending forces acting on the catheter body 112. This may reduce the riskof tearing and/or kinking of the catheter body 112, as well as thesheath 114. The bumper 1438 may have an overall hyperbolic paraboloidshape as depicted in FIGS. 14A-14F, or a hyperbolic paraboloid endconfiguration on their interface ends as depicted in FIGS. 13A-13F and15A-15F. The jackets or bumpers 1338, 1438, 1538.

The proximal and distal segments 1300, 1500 may comprise a planar end1340, 1540 to attach or interface with other components of the deliverysystem. The jackets or bumpers 1338, 1538 may comprise a non-planar endand a planar or circular end, corresponding their ends 1302, 1402, 1404,1504. The jackets or bumpers 1338, 1438, 1538 may comprise any of avariety of materials, including silicone, polyurethane, styrenicco-block polymers, PEEK, nylon, PTFE, HDPE, and the like.

FIGS. 16A to 16L depicts an exemplary embodiment of the proximalsteering and extension assemblies 124, 126 as shown in FIG. 1A. In thisparticular embodiment, the proximal steering assembly 124 comprises aflexible segmented tubular body 1600, but instead of discrete segmentsas in the distal steering assembly 128, the flexible segmented tubularbody 1600 is a lasercut, unibody flexible segmented tubular body 1600comprising segments 1602, 1604, 1606. Referring to FIG. 16M, thesegments 1602, 1604, 1606 are interconnected by a pair of living hingestruts 1608 and a pair of neck regions 1610 on opposite sides of thetubular body 1600. To each side of neck region 1610 is a wedge opening1614, which is configured to allow limited flexion between the segments1602, 1604, 1606. The wedge opening 1614 is formed by a tapered orangular gap between the proximal ends 1616 and distal ends 1618 of thesegments 1602, 1604, 1606. The maximum longitudinal separation along theopening 1614 may be in the range of 0.6 mm to 0.9 mm, 0.4 mm to 1 mm, or0.2 mm to 1.2 mm. The angle formed by the proximal and distal ends 1616and 1618 may be in the range of 5 degrees to 30 degrees, 8 degrees to 20degrees, or 10 degrees to 15 degrees. The wedge openings 1614 may be incontinuity with narrower arcuate slits 1620 from the apex 1622 of thewedge openings 1614 to the wide end 1624 of the strut 1608. A smallerwedge opening 1626 is provided between the wide end 1624 and the middleof strut 1608 and is also in communication with a smaller opening 1630at the narrow end 1632 of the interconnect 1608. The smaller opening1630 may comprise a teardrop shape, wherein the tip of the teardrop isin continuity with the tip of the smaller wedge opening 1632. Together,the larger wedge arcuate slit 1620, smaller wedge opening 1626 andteardrop opening 1630 form a partially circular configuration with apartially circular opening 1640 of one segment attached to a bifid pivothead 1642 that is able to pivot or bend within the partially circularopening 1640. The maximum bending angle between each segment 1602, 1604,1606 may in the range of 10 degrees to 45 degrees, 15 degrees to 35degrees, or 20 degrees to 30 degrees, and the maximum total bendingangle of the segmented tube 1600 may be 75 degrees to 150 degrees, 90degrees to 130 degrees, or 100 degrees to 120 degrees.

Referring to FIG. 16N, in addition the pivoting movement at each opening1640 and complementary bifid pivot head 1642, each segment 1602, 1604,1606 also comprises a pair of notches 1644 and/or protrusions 1646 whichare slidable in the notches 1644. The notches 1644 and protrusions 1646may resist torsional forces that are acting on the proximal steeringassembly 124 and/or may also provide or support the limit on the amountof flexion between each segment 1602, 1604, 1606, based on thelongitudinal length of the notches 1644 and protrusions 1646. In somevariations, the lengths of the notches may be in the range of 12 mm to25 mm, 15 mm to 22 mm, or 16 mm to 20 mm, and the lengths of theprotrusions may be in the range of 1.5 mm to 2.5 mm, 1.7 mm to 2.2 mm,or 1.8 mm to 2.0 mm. The widths of the notches and protrusions may be inthe range of 0.8 mm to 2 mm, 1.0 mm to 1.8 mm, or 1.1 mm to 1.4 mm. Thegap length between the notches and protrusions when the proximalsteering assembly is in an unbent neutral position may be in the rangeof 0.5 mm to 1.5 mm, 0.6 mm to 1.2 mm, or 0.7 mm to 0.9 mm. This gaplength may also be the maximum gap length of the larger wedge opening1614. The number of segments 1604 in the steering assembly in FIGS. 16Aand 16B is ten, but in other examples, the number may be in the range of1 to 20, 2 to 15, 5, to 15, or 8 to 12. The average longitudinal lengthof segments 1604 may be in the range of 2 mm to 10 mm, 2 mm to 6 mm, 3mm to 5 mm, or 3.5 mm to 4.5 mm. The proximal and distal segments 1602,1606 may be longer, e.g. in the range of 2 mm to 10 mm, 4 mm to 9 mm, 5mm to 8 mm, 4 mm to 8 mm, 4 mm to 5 mm, 3 mm to 6 mm, or 2 mm to 8 mm.

Referring to FIGS. 160 and 16P, each of the segments 1602, 1604, 1606comprises a central or primary opening 1648, as well as steering flanges1650 and steering openings 1652 located in the primary opening 1648 ofat least some if not all of the segments 1602, 1604, 1606. The proximaland distal segments 1602, 1606 may comprise longer and/or largersteering cavities 1654, 1656. As depicted in FIG. 16P, the steeringwires 1654 for the proximal steering assembly 124 slidably reside in theopenings 1652 and the cavities 1654, 1656. The steering element 1658 maybe attached to the distal cavity 1656 via weld, knot, crimp structure1660 or other interference fit to the steering opening to affix. Thesteering element 1658 may be located in a coil sheath 1662 or othertubular structure that is attached to the steering cavity 1654 of theproximal segment 1602 of the proximal segment 1606. The steering wiremay comprise a solid or multi-filament wire with a size in the range of0.3 mm to 0.8 mm, 0.4 mm to 0.7 mm, or 0.4 mm to 0.6 mm. Proximally, thesteering wires 1654 may be attached to lever 110 of the handle 102, asdescribed in further detail below.

Referring now to the extension assembly 126 of the delivery system inFIGS. 16A to 16K, the extension assembly 126 comprises a proximal orfirst housing 1660 with a proximal end 1662 and a distal end 1664 and isin slidable arrangement with a distal or second housing 1666, with aproximal end 1668 and a distal end 1670. A worm gear 1672 or helicallythreaded shaft is rotatably coupled to a helical lumen 1674 of theproximal housing 1660. This worm gear or lead screw shaft 1672 isconfigured to extend and retract with rotation relative to the helicallumen 1674 and the proximal housing 1660. The distal end of the screwshaft 1672 is rotatably fixed to the proximal end 1668 of the secondhousing 1666 via a screw, bolt, rivet, crimp head or other fastener 1676via an opening 1678 in the proximal end 1668. This attachment interfacepermits rotation of the screw shaft 1672 while also locking theextension and retraction of the screw shaft 1672 and the extension andretraction of the distal housing 1666 relative to the proximal housing1660. To resist any torsional displacement that may occur between theproximal and distal housings 1660, 1666, a slot 1680 and grooves 1682may be provided with one or more wall sections 1684 of the proximal anddistal housings 1660, 1666. A mechanical stop structures may be providedon the worm gear or threaded shaft to provide a limit on the amount ofextension. The proximal end of the worm gear or threaded shaft thatcontrols this extension may be mechanically coupled to a rotatable knob106 on the handle 102, which is described below.

As noted previously, control of implant expansion, steering and catheterextension may be performed using a number of controls 104, 106, 108, 110provided on the handle 102, as depicted in FIGS. 17A to 17E. Forrotation of the rotor assembly 850 900 depicted in FIGS. 8A to 9F, therotor assembly 850, 900 may be coupled to a drive shaft 1700 in thehandle 102 and attached to rotatable knob 104. The knob 104 may comprisea knob body 1702, which is exposed via one or more housing openings 1704of the handle 102 to permit user rotation. The knob body 1702 maycomprise one or more ridges 1706 to facilitate gripping of knob 104 andto resist slippage during use. The knob 104 may also comprise asecondary knob body 1708 comprises ridges or teeth that are releasablyengageable by the lock assembly 130. When engaged, the locking head orstructure 1712 of the lock assembly 130 engages the teeth to resistrotation of the knob 104. The locking head 1712 is attached to one ormore struts 1714 to the lock lever 1716, and is biased to the engagedposition by one of more springs 1718 provided on the struts 1714. Todisengage the locking head 1712, the lock lever 1716 is depressed orsqueezed, to thereby pivot at its housing joint 1720 and to overcome theresistance of the springs 1718 to disengage the locking head 1712.

The drive shaft 1700 is located in the tubular stator shaft 1730 locatedin the handle 102. To resist rotational movement of the stator shaft1702 during manipulation of the delivery system, a stator key block 1732is attached to or clamped to the stator shaft 1730 via a set screw orpin. The shape of the block 1704 forms a complementary interfit with theshape of the elongate block cavity 1736 resist rotational displacementwhile allowing longitudinal movement of the block 1704 in the cavity1736. The longitudinal displacement permits the extension and retractionof the distal region of the delivery system as the extension assembly126 is adjusted during the procedure. As noted previously the worm gearand threaded interface of the extension assembly 126 is configured togenerate the longitudinal displacement force to extend and retract thesecond housing of the extension assembly, a similar threaded interface1738 may be provided in the handle 102 to provide a second location atthe proximal end of the worm gear shaft 1740 to help push or pull thestator shaft to help alleviate any resistance to the displacement of thestator shaft as it travels with the second housing of the extensionassembly. The proximal threaded interface 1738 may comprise a keyedstructure 1742 that permits extension and retraction of the stator shaft1730 by exerting force on a proximal flange 1744 of the stator shaft1730 at its proximal end during with use of the extension assembly 126.

Next, the control 108 of the 4-way distal steering assembly 128 may beprovided with a joystick handle 1750. The joystick handle 1750 isconfigured with an articulation 1752 to pivot in at least fourdirections and/or a combination of the two the four directions,comprises steering element attachment structures 1754 to apply tensionforces of varying amounts through the steering wire or elements (notshown) to bend the distal steering assembly 128. One or more steeringwire or element guides 1756, 1758 may be provided to provide facilitatethe bends in the steering wire or elements through which the tension istransferred. Similarly, the control 110 of the two-way proximal steeringassembly 124 comprises a pivotable lever 1760 to which steering wires orelements are attached at attachment structures 1762 along the lever1760. As the lever 1760 is rotated in one direction or the otherdirection from its neutral position, tension is generated in one of thesteering wires or elements while relieving or reducing tension, if any,in the other steering wires or element. The lever 1760 may be maintainedin a neutral position when not manipulated by the user either by one ormore pairs of opposing springs acting on the lever 1760 or by setting abaseline balanced tension in the steering wires or elements.

In another embodiment of a delivery device, depicted in FIG. 19A, thedelivery device 1900 comprises two two-way steering assemblies 1924,1928, without an extension assembly. In some configurations, bothassemblies 1924, 1928 are configured to bend in the same bending plane,both in other configurations, the assemblies bend in different bendingplanes, e.g. bending planes that are orthogonal to each other. These andother components are otherwise similar to the delivery device 100described earlier, including the rotor, stator, sheath, and adapted forthis particular delivery device 1900. For example, the proximal end ofthe delivery device 1900 includes a handle 1902 with controls 1904,1906, 1908 that are coupled to the catheter body 1912, along with aslidable sheath 1914 and sheath handle 1916. The control of the rotorshaft via the rotary knob 1940 of control 1904 and releasable lock 1930are otherwise similar to the mechanism for the control 104 andreleasable lock 130 of delivery device 100. The knob 1940 is fixedlyattached to the rotor shaft 1942 to control the unwinding and release ofthe tension members in the implant delivery section of the deliverydevice 1900. The releasable lock 1930 comprises a lock lever 1932 thatis attached to the handle 1902 via a pin joint 1934 or otherarticulation. The lever 1932 is maintained in a biased lockconfiguration via a spring 1936 that pulls the locking head 1938 intoengagement with the secondary body 1944 of the knob 1940 to resistrotation. Upon depression or squeezing of the lever 1932 to overcome thespring force and to separate the locking head 1938 away from thesecondary body 1944, the knob 1940 may be rotated by the user. Incontrast to delivery device 100, the stator shaft 1950 of deliverydevice 1900 does not longitudinally displace due to the lack of anextension assembly, but may be coupled to the handle 1902 via anadhesive bond and/or a mechanical interfit or interference interface. InFIGS. 19B to 19E, for example, the stator shaft 1950 is coupled to astator key block 1952 via a set screw or other mechanical fastener. Theblock 1952 is located in a block cavity 1954 with a complementary cavityshape to the outer surface of the stator key block 1952 to therebyresist rotational and longitudinal displacement.

The bending controls 1906 and 1908 may comprise a configuration similarto control 110 of delivery device 100. These controls 1906, 1908 eachcomprise a lever 1960 with a central pivot joint 1962 that with steeringelement attachment structures 1964 located on each side of the levers1960. The steering wires or elements 1966 (depicted only on one side ofthe handle 1902) are coupled to the attachment structures 1964 and alongsteering guides 1968 and into the catheter body 1912, external to thestator shaft. Optional steering wire sheaths or compression coils 1970may be provided to facilitate movement of the steering elements 1966.The steering elements 1966 may be routed in any of a variety of ways asshown in FIGS. 19B to 19E, but may also be routed radially inward closerto the central pivot 1962 and clamped in between the attachmentstructures 1964 on each side.

In one exemplary method of delivering the replacement valve, the patientis positioned on the procedure table, and the draped and sterilized inthe usual fashion. Anesthesia or sedation is achieved. Percutaneous orcutdown access to the vascular or entry site is obtained, e.g. at thefemoral vein, femoral artery, radial artery, subclavian artery, and anintroducer guidewire is inserted. A guidewire is manipulated to reachthe desired valve implantation site. Pre-shaped guidance catheters orballoon catheters may be used to facilitate the crossing of the valveimplantation site

Referring to FIG. 4A, the delivery system 400 with the delivery catheter402 and valve 804 is positioned across the valve opening 406. Thedelivery system 400 may also be further manipulated to adjust the angleof entry through the valve opening 406 to be roughly orthogonal to thenative valve opening and/or to be centered with the valve opening 406.Once the desired catheter pose is achieved, the delivery sheath 408 iswithdrawn proximally, to expose the collapsed valve 404.

In FIG. 4B, the set of tension lines 428 controlling the release of thedownstream end 410 of the outer wall 412 of the valve 404 are partiallyreleased, while the tension lines controlling the inner wall 416 remaintensioned. Next, in FIG. 4C, downstream end 410 of the outer wall 412 ofthe valve 404 is further released, allowing the downstream end, themiddle region and more of the upstream end 414 of the outer wall 412 toexpand further, thereby allowing the transition wall 416 of the valve402 to at least partially expand outward. The partial expansion of theatrial end 414 and the ventricular end 410 of the valve 402 helps tofurther center and orient the middle region 422 of the valve 402orthogonally prior to complete release. While the initial expansion ofthe atrial end 414 of the outer wall 412 in this embodiment is asecondary effect from the partial release of the ventricular end 410 ofthe valve 402 as longitudinal tension is released, in other examples,independent tension line control of the upstream end 414 may beprovided.

In FIG. 4D, the tension lines 428 of the downstream end 410 and thetension lines 430, 432 of the upstream end 414 are further released,either simultaneously or singly in a stepwise fashion, further engagingthe middle region 420 of the outer wall 412 against the valve opening406. This further expansion of the outer wall 412 also exposes theretention barbs or projections 422 on the outer wall 412. Propercentering and orientation of the valve is reconfirmed, to make sure thevalve has not been deployed in a skewed or partially disengaged posewith respect to the valve annulus. The tension lines 428, 430, 432 maybe optionally re-tensioned to re-collapse the valve 404 may beperformed, to facilitate re-positioning and/or re-orienting of the valve404. Once confirmed, the tension lines of the inner wall 818 arereleased, as shown in FIG. 4E, which also allows the outer wall 412 toachieve its untethered expansion against the mitral valve opening 406.The tension lines 428, 430, 432 can then be separated from the valve 404and withdrawn into the catheter and optionally out of the proximal endof the catheter 402. Alternatively, the delivery system and procedure inFIGS. 5A to 5E may be adapted for a similar delivery procedure.

In still another exemplary method of delivering the replacement valve,the patient is positioned on the procedure table, and the draped andsterilized in the usual fashion. Anesthesia or sedation is achieved,with selective ventilation of the right lung and optionally the leftupper lobe of the lung to permit controlled collapse of the left lowerlobe of the lung. A pursestring suture is placed at the transapical orother cardiac entry site. A trocar is inserted through a cannula orintroducer with a proximal hemostasis valve, and the trocar assembly isinserted through the pursestring suture to access the cardiac chamberand the target valve.

Referring to FIG. 4A, the delivery system 400 with the delivery rigidtool 402 and valve 404 is positioned across the valve opening 406. Thedelivery system 400 may also be further manipulated to adjust the angleof entry through the valve opening 406 to be roughly orthogonal to thenative valve opening and/or to be centered with the valve opening 406.Once the desired tool pose is achieved, the delivery sheath 408, if any,is withdrawn proximally, to expose the collapsed valve 404.

In FIG. 4B, the tension lines 438 controlling the release of thedownstream end 410 of the outer wall 412 of the valve 804 are partiallyreleased, while the tension lines 430, 432 controlling the inner wall416 remains tensioned. Next, in FIG. 4C, downstream end 410 of the outerwall 412 of the valve 404 is further released, allowing the downstreamend, the middle region and more of the upstream end 414 of the outerwall 412 to expand further, thereby allowing the transition wall 416 ofthe valve 402 to at least partially expand outward. The partialexpansion of the atrial end 414 and the ventricular end 410 of the valve402 helps to further center and orient the middle region 422 of thevalve 402 orthogonally prior to complete release. While the initialexpansion of the atrial end 414 of the outer wall 412 in this embodimentis a secondary effect from the partial release of the ventricular end410 of the valve 402 as longitudinal tension is released, in otherexamples, independent control of each tension line may be provided.

In FIG. 4D, the tension lines of the downstream end 410 and upstream end414 are further released, either simultaneously or singly in a stepwisefashion, further engaging the middle region 420 of the outer wall 412against the valve opening 406. This further expansion of the outer wall412 also exposes the retention barbs or projections 422 on the outerwall 412. The tension lines may be optionally re-tensioned tore-collapse the valve 404 may be performed, to facilitate re-positioningand/or re-orienting of the valve 404. Proper centering and orientationof the valve is reconfirmed, to make sure the valve has not beendeployed in a skewed or partially disengaged pose with respect to thevalve annulus. Once confirmed, the tension lines of the inner wall 418are released, as shown in FIG. 4E, which also allows the outer wall 412to achieve its untethered expansion against the mitral valve opening406. The tension lines 428, 430, 432 can then be released as shown anddescribed for FIGS. 10G and 10H, or cut with the cut ends withdrawn intothe catheter and optionally out of the proximal end of the delivery tool402. Alternatively, the delivery system and procedure in FIGS. 5A to 5Emay be adapted for a similar delivery procedure.

In some embodiments, the delivery system may be configured with anattachment interface proximal to the implant delivery section. Thisallows the attachment of the implant delivery section to the rest of thedelivery system at the point of manufacture or at the point of use,during the assembly process or final step of the assembly procedure orpreparation procedure. The attachment interface may facilitate theattachment of different handles, steering assemblies and/or differentsize implants during the manufacturing process or during clinical use.The attachment interface may also facilitate the separate packaging andsterilization of different components delivery system, which may havedifferent packaging or sterilization requirements, thereby simplifyingthe manufacturing process, e.g. different sterilization and packaging ofa pre-attached valve and/or pre-routed tension members to thestator/rotor assembly, vs. the handle and catheter body of the deliverysystem.

The location of the attachment interface of the delivery system mayvary, depending on the features provided for the delivery system. Forexample, the attachment interface may be located within the distalcatheter section, between a distal steering mechanism and the implantdelivery section, or may be located at the proximal end of the distalcatheter section, between the catheter body and the proximal end of thedistal catheter section or implant delivery section, depending onwhether any steering or extension assembly is provided.

FIGS. 20A to 20D and 21A to 21B, for example, depicts an exemplaryembodiment of the attachment interface 2000 of a delivery system that,for simplification, does not depict a steering or extension mechanism,that may be included. The attachment interface 2000 comprises a proximalattachment interface 2002 and distal attachment interface 2004. Theproximal attachment interface 2002 comprises a proximal outer tubeinterface 2006, a drive shaft interface 2008, and the distal attachmentinterface 2004 comprises a stator tube interface 2010 and a rotor shaftinterface 2012 (depicted in FIG. 21A), coupled to the stator housing2014 and the rotor shaft 2016, respectively. The proximal outer tube2006 and the stator tube interface 2010, and the drive shaft interface2008 and the rotor shaft interface 2012, are configured to be engaged toform a mechanical interfit that resists longitudinal detachment and/orrotational separation when engaged. As illustrated in FIGS. 20A and 20B,the proximal outer tube 2006 may be attached or bonded to the end of thecatheter body 2018, or steering/extension assemblies if provided. Theproximal outer tube 2006 comprises a plurality of cut-outs or recesses2020 located along the rim of the opening of the proximal outer tube2006. These recesses 2020 form a complementary mechanical interfit witha plurality of projections 2022 of the stator tube interface 2010.Similarly, the drive shaft interface 2008 may comprise a plurality ofrecesses 2024, which in turn is configured to form a mechanical interfitwith a plurality of projections 2026 of the rotor shaft interface 2012.Once the proximal and distal attachment interfaces 2002, 2004 areengaged, torque from the handle of the delivery system may betransmitted through the drive shaft interface 2008 and rotor shaftinterface 2012 to the rotor shaft 2016, to adjust the tension members.

Once engaged, the attachment interface 2000 may be maintained in theengaged configuration with one or more locking structures or a lockingassembly. For example, in FIGS. 20A to 21B, the locking interface maycomprise a locking collar 2040 and a securing component 2042, where thelocking collar 2040 resists transverse movement of the attachmentinterface 2000 when engaged and wherein the securing component 2042,which may be a pin or a resilient C-ring, resists the longitudinaldisplacement or disengagement of the locking collar 2040, when thesecuring component is engaged to one or more securing recesses 2044located on the stator tube interface 2010.

In this particular example, as depicted best in FIG. 21B, the recesses2020 each configured with a neck region 2024 that has a narrower widththan a head region 2026, and the projections 2022 are each similarlyconfigured with a neck region 2028 that is narrower in width than itshead region 2030. The neck regions 2024 of the recesses 2020 form acomplementary interfit with the head regions 2030 of the projections2022, and the head regions 2026 of the recesses 2020 for a complementaryinterfit with the neck regions 2028 of the projections 2022. Thisconfiguration allows the engagement of the recesses 2018 and theprojections 2024 by permitting transversely translating the recesses2018 and 2024 into engagement, but resisting longitudinal translationonce engaged, as the wider head regions 2030 of the projections 2022resist longitudinal displacement through the narrower neck regions 2024of the recesses 2020. When engaged, the locking collar 2040 may then belongitudinally displaced proximally from an unlock position where theattachment interface 2000 is uncovered or exposed, to a locked positionwhere the locking collar 2040 covers the attachment interface 2000 sothat transverse translation to separate the recesses 2020 andprojections 2022 is resisted. In the particular example in FIGS. 20A to21B, the head/neck configuration is a slightly angled keystone ortrapezoidal shape which correspond to the larger head and narrower neckregions, with an angle in the range of 1 to 10 degrees or 2 to 5degrees, but in other variations, a greater angle up to 20 degrees, 30degrees or 45 degrees may be provided.

Similarly, referring to FIG. 21A, the plurality of recesses 2050 of thedrive shaft interface 2008 may comprise head and neck regions 2052,2054, respectively, that form a complementary mechanical interfit withthe neck and head regions 2058, 2060, respectively of the projections2056 of the rotor shaft interface 2012. The head and neck regions 2052,2054, 2058, 2066 may also have angled sides so that the recesses 2032and the projections 2038 may be engaged by transverse translation, butresist longitudinal separation once engaged.

Referring still to FIGS. 20A to 21B, to facilitate the transverseengagement of the attachment interface components, certainconfigurational features may be provided. Referring to the example inFIG. 22, the attachment interface 2200 comprise a proximal attachmentinterface 2202 on a distal end of a proximal structure of the deliverysystem, and a distal attachment interface 2204 on a proximal end of thecorresponding distal structure of the delivery system. The proximalattachment interface 2202 comprise an outer tube interface 2206, and adrive shaft interface 2208 with a guidewire or central lumen 2210. Theouter tube interface 2206 comprises four recesses 2212 a-b, 2214 a-b,and the drive shaft interface 2208 comprises two drive shaft engagementsurfaces or recesses 2216 a-b. The complementary distal attachmentinterface 2204 comprises a stator tube or housing 2218 with fourprojections 2220 a-b, 2222 a-b, and a rotor shaft interface 2224 withtwo projections 2226 a-b or yoke arms. To facilitate the transverseengagement, the sides of recesses 2212 a and 2212 b are aligned on eachside with each other along with the sides of corresponding projections2220 a and 2220 b. In addition, the sides of the recesses 2212 a, 2212 band projections 2220 a and 2220 b that are closer to the center of thedelivery system are also aligned with the recess 2216 a of the driveshaft 2208 and the engagement surface of the corresponding arm orprojection 2226 a of the rotor shaft interface 2224. The drive shaftrecess 2216 a and the arm or projection 2226 a are also aligned witheach other. Likewise, the sides of recesses 2214 a and 2214 b arealigned on each side with each other along with the sides ofcorresponding projections 2222 a and 2222 b, and the sides of therecesses 2214 a, 2214 b and projections 2222 a and 2222 b that arecloser to the center of the delivery system are also aligned with therecess 2216 b of the drive shaft 2208 and the corresponding arm orprojection 2226 b of the rotor shaft 2224, and where the drive shaftrecess 2216 b and the arm or projection 2226 b are also aligned witheach other. Together, the described alignments of these structures allowthe transverse engagement of the proximal and distal attachmentinterfaces 2202, 2204 while the wider/narrower regions of the recessesand projections described earlier provide resistance to longitudinalseparation once engaged.

The total gap or difference between the inner diameter of the lockingcollar and the outer diameter of the outer tubing interface may be inthe range of 10 μm to 1000 μm, or 100 μm to 800 μm, or 200 μm to 500 μm.The gap may be selected to reduce the movement friction of the lockingcollar movement while limiting any play between the proximal and distalinterfaces of the attachment interface that may result in partialdisengagement at the attachment interface. The gap may be smaller thanthe radial thickness of the proximal and/or distal interfaces of theouter tubing and stator structures.

Although the embodiment depicted in FIGS. 20A to 22 is configured atboth the outer tubing/stator housing and the drive shaft/rotor shaft toresist longitudinal separation, in other variations, only the outertubing/stator housing interface may be configured to resist longitudinalseparation, while the drive shaft/rotor shaft interface may not beconfigured to resist longitudinal separation, or where only the driveshaft/rotor shaft interface may be configured to resist longitudinalseparation, but the outer tubing/stator housing interface may not beconfigured to resist longitudinal separation. These variations mayprovide greater tolerances and ease of use during transverse engagementof the attachment interface. In still other variations, the lockingcollar may be configured to resist longitudinal separation via barbs andrecesses, such that neither the outer tubing/stator housing interfacenor the drive shaft/rotor shaft interface are configured to resistlongitudinal separation. In still other variations, one or more of thecomplementary features on the proximal attachment interface and thedistal attachment interface may be reversed in their locations.

Referring back to FIG. 22, the alignments of the various structuresallow the transverse engagement to be performed bi-directionally, e.g.starting with recesses 2212 a, 2214 a with projections 2220 b, 2222 b,or starting with recesses 2212 b, 2214 b and projections 2220 a, 2222 a.In other variations, as shown in FIGS. 23 and 24, the alignments andsizes of the various structures may be configured to only allowtransverse engagement to performed in one direction only. Aunidirectional interface may make it easier for the user or assembler toseat the projections into the recesses by providing or one or more stopsurfaces to facilitate alignment during the engagement at the attachmentinterface, which may make alignment of the proximal and distalattachment interfaces easier and reduce the potential risk of jammingduring engagement.

Referring to FIG. 23, the attachment interface 2300 comprises a proximalattachment interface 2302 on a distal end of a proximal structure of thedelivery system, and a distal attachment interface 2304 on a proximalend of the corresponding distal structure of the delivery system. Theproximal attachment interface 2302 comprise an outer tube interface2306, and a drive shaft interface 2308 with a guidewire or central lumen2310. The outer tube interface 2306 comprises four recesses 2312 a-b,2314 a-b and the drive shaft interface 2308 comprises two drive shaftengagement surfaces or recesses 2316 a-b. The complementary distalattachment interface 2304 comprises a stator tube or housing interface2318 with four projections 2320 a-b, 2322 a-b, and a rotor shaftinterface 2324 with two projections 2326 a-b or yoke arms. In thisembodiment, recess 2312 a is smaller than recess 2312 b and projection2320 b, with respect to their widths along the transverse translationaxis, and projection 2320 a is smaller than recess 2312 b and projection2320 b, but recess 2312 a is aligned with projection 2320 a, and recess2312 b is aligned with projection 2322 b. Recess 2316 a of the driveshaft interface 2308 and the corresponding arm or projection 2326 a ofthe rotor shaft interface 2324 remain aligned, with arm or projection2326 a configured by size and location to clear recess 2312 b. Likewise,recess 2314 a is smaller than recess 2314 b and projection 2322 b withrespect to their widths along the transverse translation axis, andprojection 2322 a is smaller than recess 2314 b and projection 2322 b,but recess 2314 a is aligned with projection 2322 a, and recess 2314 bis aligned with projection 2322 b. Recess 2316 b of the drive shaft 2308and the corresponding arm or projection 2326 b of the rotor shaft 2324remain aligned with each other, with arm or projection 2326 b configuredto clear recess 2314 b.

FIG. 23 depicts multiple partial alignments and size differences tofacilitate the seating of the distal attachment interface 2304 into theproximal attachment interface 2302, but some of the angular and sizechanges between the bi-directional embodiment in FIG. 22 and theunidirectional embodiment in FIG. 23 may cause, during torqueing of thedelivery system, some mechanical bias or forces that may cause theproximal and distal attachment interfaces 2302, 2304 to twist apart orout of full alignment. In other variations of the attachment interface,a subset of the alignment/seating features described in FIG. 23 may beimplement, to achieve a different balance of between ease of seating,mechanical integrity and other factors.

FIGS. 24 and 25 depict additional schematic variations of an attachmentinterface 2400 wherein the proximal attachment interface 2402 comprisestwo lateral alignment bodies 2404, two channels 2406, two centralalignment bodies 2408 with a drive shaft cavity 2410 there between andan oblong drive shaft head 2412 and central lumen 2414. The distalattachment interface 2416 comprises two paramedial alignment bodies 2418configured to be inserted into the channels 2406, a central channel 2420configured to receive the two central alignment bodies 2408 and thedrive shaft head 2412 a central rotor shaft cavity 2422 in which tworotor shaft arms or projections 2424 are configured to receive andengage the oblong drive shaft head 2412. Although all of the structuresand surfaces of this embodiment of the engagement interface areparallel, in other variations, one or more surfaces may be angled, andor comprise additional recesses/cutouts 2500 and flanges/projections2502, as depicted in FIG. 25.

While the embodiments herein have been particularly shown and describedwith references to embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the scope of the embodiments. For all ofthe embodiments described above, the steps of the methods need not beperformed sequentially.

What is claimed is:
 1. A delivery system, comprising: a proximal handlecomprising a handle housing and a first actuator; a catheter bodycoupled to the handle, the catheter body comprising a distal section, aproximal section and a middle section therebetween; a rotatable driveshaft coupled to the first actuator and located in the catheter body; afirst stator housing attached to the catheter body, the first statorhousing comprising an internal opening and an external opening; a firstrotor disc attached to the rotatable drive shaft and located in thefirst stator housing, the first rotor comprising a plurality of tensionline attachment sites; and a movable sheath located over the catheterbody.
 2. The delivery system of claim 1, further comprising: aself-expanding implant, the implant comprising a contractedconfiguration and an expanded configuration; and a first tensioningmember releasably coupled to the self-expanding implant and fixedlycoupled to the attachment site of the first rotor.
 3. The deliverysystem of claim 2, wherein the first tensioning member is further woundaround the first rotor.
 4. The delivery system of claim 3, wherein thefirst tensioning member is wound around the first rotor at least threetimes.
 5. The delivery system of claim 1, wherein the proximal handlefurther comprise a first actuator lock, wherein the first actuator lockcomprises locked and unlocked configurations and is biased to the lockconfiguration.
 6. The delivery system of claim 1, further comprising acatheter extension assembly configured to reversibly adjust alongitudinal spacing between the distal section and the middle sectionof the catheter body.
 7. The delivery system of claim 6, wherein thecatheter extension assembly comprises a proximal housing with a proximalthreaded lumen, a distal housing and a threaded extension shaft locatedin the proximal threaded lumen and coupled to the distal housing.
 8. Thedelivery system of claim 7, wherein the proximal housing and distalhousing comprise a slotted interface therebetween to resist rotationaldisplacement therebetween.
 9. The delivery system of claim 7, whereinthe proximal handle further comprises a second actuator coupled to thethreaded extension shaft.
 10. The delivery system of claim 6, furthercomprising a first steering assembly comprising a first segmentedtubular body and a first plurality of elongate steering wires.
 11. Thedelivery system of claim 10, wherein the first steering assembly islocated proximal to the catheter extension assembly.
 12. The deliverysystem of claim 10, wherein the first segmented tubular body comprises alaser-cut tubular body.
 13. The delivery system of claim 10, furthercomprising a second steering assembly comprising a second segmentedtubular body and a second plurality of steering wires.
 14. The deliverysystem of claim 10, wherein the second steering assembly is locateddistal to the catheter extension assembly.
 15. The delivery system ofclaim 13, wherein the first steering assembly and second steeringassembly comprise different bending configurations.
 16. The deliverysystem of claim 13, wherein the first steering assembly comprises atwo-way steering assembly and the second steering assembly comprises afour-way steering assembly.
 17. The delivery system of claim 13, whereinthe first segmented tubular body comprises segments attached by livinghinges.
 18. The delivery system of claim 17, wherein the secondsegmented tubular body comprises a plurality of discrete segments. 19.The delivery system of claim 18, wherein each of the plurality ofdiscrete segments comprises one or two non-planar end openings.
 20. Thedelivery system of claim 19, wherein the non-planar end openingscomprise a hyperbolic paraboloid shape.
 21. The delivery system of claim20, wherein the each of the plurality of discrete segments comprises aperimeter bumper.